Notched door valve for control of carburetor air and crankcase vapors

ABSTRACT

An air cleaner snorkel having an inlet for heated air in addition to the usual ambient air inlet at its open end and also including an inlet for vapors from the crankcase. A door-like valve controls the flow of ambient and heated air through the snorkel into the air cleaner. The door is notched to assure the presence of at least a small amount of ambient air flow through the snorkel when the door is closed or partially so with respect to the ambient air inlet thereby directing vapors from the crankcase into the air cleaner and preventing their escape out of the ambient air inlet to the atmosphere.

United States Patent Sarto et al.

[54] NOTCHED DOOR VALVE FOR CONTROL OF CARBURETOR'AIR AND CRANKCASEVAPORS [72] Inventors: Jorma O. Sarto, Orchard Lake; Gary D. Dawson,Rochester, both of 21 Appl. No.: 101,228

[52] US. Cl. ..123/l19 B, 123/122 D [51] Int. Cl. ..B0ld 39/10, F02m23/14, F02f 9/02 [58] Field oiSearch 123/122 D, 119 B 1 [56} ReferencesCited UNITED STATES PATENTS 2/1957 Sebok et a1. ..l23/122 D 1/1958 Dolza..l23/122 D [451 Dec.5, 1972 Scott ..123/122 D X PrimaryExaminer-Wendell E. Burns Attorney-Talburtt & Baldwin [5 7 ABSTRACT Anair cleaner snorkel having an inlet for heated air in addition to theusual ambient air inlet at its open end and also including an inlet forvapors from the crankcase. A door-like valve controls the flow ofambient and heated air through the snorkel into the air cleaner. Thedoor is notched to assure the presence of at least a small amount ofambient air flow through the snorkel when the door is closed orpartially so with respect to the ambient air inlet thereby directingvapors from the crankcase into the air cleaner and preventing theirescape out of the ambient air inlet to the atmosphere.

5 Claims, 4 Drawing Figures PATENTEUBEB 5 I972 v sum 1 OF 2 INVENTgLi77% J47 0 7 Z llama)! PATENTED DE 5 I97? 3. 704,698

sum 2 or 2 2-4:. 1% INVENTORS.

NOTCHED DOOR VALVE FOR CONTROL OF CARBURETOR AIR AND CRANKCASE VAPORSBACKGROUND This invention relatesto crankcase ventilating arrangementsand a means for preventing the loss of crankcase vapors to theatmosphere. Certain crankcase ventilator arrangements make use of acrankcase inlet conduit or back-up tube which communicates between thecrankcase and the carburetor air cleaner snorkel. At certain timesduring engine operation this conduit carries fuel-rich vapors from thecrankcase to the snorkel.

Certain air cleaners today make use of heated inlet air to permit theuse of leaner fuel-air mixtures. Such arrangements include an extra airinlet into the snorkel for the heated air. A sheet metal stoveis boltedover 0 the inlet manifold that is a downstream portion of the I theexhaust manifold and air drawn therebetween for heating is carried tothe snorkel by a suitable conduit. A thermostatically controlled-vacuumoperated doorlike air valve controls the air temperature to apredetermined temperature, such as l00F.

When these arrangements are combined into one system there is somedanger of the loss of crankcase vapors out the open end of the snorkel.It is the purpose of this invention to prevent such losses.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is aschematic showing of a closed engine ventilator system including inletand outlet ventilator conduits to the crankcase from different parts ofthe engine induction system; the inlet conduit or back-up tube extendingbetween the carburetor air cleaner snorkel and one crankcase inletpassage is arrangedas part of the improved combination according to thisinvention.

FIG. 2 is a schematic showing of a heated inlet air system including themanifold heating arrangement and the vacuum operated thermostaticcontrol for the air control valve.

FIG. 3 is a side view, partly in section, of a carburetor air cleanersnorkel body showing the air control valve in the closed positionrelative to the ambient air inlet and also showing the preferredlocation for the point of attachment of the back-up tube to the snorkelbody.

FIG. 4 is a plan view of FIG. 3 with portions removed to show theapertured air control valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT Closed crankcase ventilationsystems have been used on many automobiles for several years. Such asystem is described in detail in SAE Paper No. 700150, entitled ChryslerEvaporation Control System, The Vapor Saver for 1970, by J. O. Sarto, W.S. Fagley and W. A. Hunter and in SAE Paper No. 700151, entitled TheChrysler Cleaner Air System for 1970, by R. E. Goodwillie, N. M. Jacoband E. W. Beckman. In such a system the inlet and outlet ventilationpassages or conduits to the crankcase are connected to the engineinduction system. The crankcase inlet ventilator conduit extends betweenthe air cleaner, which represents an upstream portion of the inductionsystem, and an inlet passage into the crankcase, such as the crankcaseair cleaner. The crankcase outlet ventilator conduit extends betweenanother crankcase outlet passage and induction system. Under engineoperating conditions, of light load, air from the carburetor air cleanerpasses through the crankcase inlet ventilator conduit into the crankcaseand sweeps blow-by gases collected therein through the crankcase outletventilator conduit and into the inlet manifold. However, during certainoperating conditions, such as heavy acceleration or wide open throttle(WOT), the flow in the crankcase inlet ventilator conduit is reversedand blow-by gases from the crankcase flow through the crankcase inletventilator conduit to the carburetor air cleaner (hence the term back-uptube) and into the induction system as well as through the outletventilator conduit. This flow reversal also occurs during enginestart-up.

FIG. 1 shows a closed engine ventilating system and the ventilator flowtherethrough, as indicated by the arrows, at light loads such as atidle. Engine 10 includes crankcase 12 and an engine induction systemwhich may consist of a carburetor air cleaner snorkel l4 having a freshair inlet and passage communicating with carburetor air cleaner 16, acarburetor 18 including an upper induction conduit 20 communicating withair cleaner 16 and a throttle valve 22 and finally an inlet manifoldmeans 24, which communicates with a combustion chamber 26. The systemalso includes ventilator outlet means which may consist of a crankcaseventilator valve 28 and a first crankcase ventilator conduit 30 whichextends between valve 28 and inlet manifold 24 via the carburetorinduction conduit. The ventilator inlet means for the system consists ofa crankcase inlet means such as crankcase air cleaner 32 whichcommunicates with the engine crankcase. Connectedbetween snorkel l4 andcrankcase air cleaner 32 is a second crankcase ventilator conduit orback-up tube 34, which functions at light loads and idle as a ventilatorinlet conduit to the crankcase. 7

As indicated hereinabove, and as shown in FIG. 1, at light engine loadsuch as at idle, fresh air flows from the snorkel through back-upconduit 34 into crankcase l2 picking up blow-by vapors and exits throughvalve 28 and crankcase ventilator conduit 30 to be directed to thecombustion chamber via inlet manifold 24. However, at heavy loads suchas wide open throttle, starting or heavy acceleration, the direction offlow in back-up conduit 34 reverses and blow-by vapors and othercrankcase vapors flow out of both the crankcase ventilator conduit 30and back-up conduit 34 into the engine induction system.

Heated intake air is supplied to the carburetor by conduit 36 and anarrangement which is best shown in FIG. 2. A sheet metal stove 38 isattached to the exhaust manifold 40. Underhood air entering the stove isheated as it passes over the hot manifold. The heated air is conductedfrom stove 38 to the carburetor snorkel 14 on air cleaner 16 through asuitable conduit arrangement indicated by 36 and 42. A thermostaticallycontrolled air valve door 44, the thermostat being a standard bimetaltype indicated at 46 and arrangedto control the application of manifoldvacuum in conduits 48 and 50 to a vacuum diaphragm actuator 52 whichoperates door 44, controls the air temperature entering air cleaner 16.With this arrangement air cleaner 16 thermostatically controls theinduction air temperature at somexdesired-value, such as 100 7F.,through an upper speed limit, such as 70 mph road loadoperation. Athigher speeds, decreasing manifold vacuum and increasing differentialpressure across the temperature control door valve cause the door toopen gradually until a manifold vacuum of say 5.5 inches of Hg isreached. At that time heat control door 44 closes the heated air inlet.Under these conditions, as is true for wide open throttle operation atall speeds, the'induction air temperature is the same as the underhoodtemperature. The use of a heated air system does not materially increasethe induction air temperature during warm weather operation but it doesraise the intake temperature in cold weather. The decreased spread intemperature range permits the use of leaner fuel-air mixtures forreduced emissions while maintaining good drivability the year round.

The vacuum operated, bimetal controlled door 44 is best seen in FIGS. 3and 4, particularly as it is modified by this invention. In FIG. 3, door44 is shown mounted in the carburetor air inlet snorkel such that it hastwo fully closed positions 44a and 44b (shown in phantom) at theopposite extremes of its travel about mounting hinge 54. Position 44a isfully closed with respect 'to ambient air inlet 46 at the open end ofsnorkel 14. Position 44b is fully closed with respect to heated airinlet 58 in the floor of the snorkel body; Of course, there are aplurality of intermediate door positions between the two extremesatwhich the door may be placedby actuator arm 60 which operably connects.door 44 to the vacuum diaphragm actuator means 52 thus providingmixtures of ambient and heated air to the air cleaner.

Back-up tube or conduit 34 is preferably connected to snorkel 14 asshown proximate an edge of door 44 with at least a portion of itsopening into snorkel I4 slightly upstream of the door edge when door 44is canted upward in position 44a, although it may be placed in otherpositions in the snorkel.

As previously stated, back-up tube 34 dumps fuelrich vapors into snorkel14 at various times during engine operation. There is some danger thatthese vapors may escape out open end 56 of snorkel 14. This isparticularly true when door 44 is in position 44a. This inventioneliminates this problem by providing door 44 with an aperture, such asnotch 62, best seen in FIG. 4, whereby a small amount of ambient airleakage is allowed past door 44 thus assuring that the flow of vapors ofback-up tube 34 is always inwardly directed toward air cleaner 16. Inthe relative positions shown, the notch and adjacent back-up tube 34further assure dilution of these vapors by ambient fresh air anddecrease the problem of hot start die-out also. 7

Having described a preferred embodiment of the invention, theembodiments thereof in which an exclusive property right is claimed areas follows:

1. In a thermostatically controlled heated inlet air system for the airinduction passage of an internal combustion engine:

a carburetor having air inlet means including an ambient air inlet and aheated air inlet;

an apertured air control door for selectively controlling the flow ofambient and heated air through the inlets;

thermostatically controlled actuator means movably mounting the door inthe carburator air inlet means such that the door has two fully closedpositions at the opposite extremes of its travel, one each with respectto the ambient air inlet and the heated air inlet respectively, and aplurality of intermediate positions therebetween whereby ambient air,heated air and mixtures thereof may -be admitted to the carburetor airinlet means, and

a back-up tube connected'to the carburetor air inlet means for carryingvapors from the engine crankcase to the carburator air' inlet means,

whereby the aperture in the air control door assures the presence of atleast a small amount of ambient air flow through the air inlet meanswhen the door is closed relativeto the ambient air inlet and the engineis running thereby directing vapors from the back-up tube into thecarburetor and preventing their escape out the ambient air inlet to theatmosphere.

2. The combination as defined by claim 1 wherein the carburetor airinlet means comprises an air cleaner having a snorkel air inlet passage.

3. The combination defined by claim 2 wherein the ambient air inletcomprises the open endof the snorkel and the heated air inlet comprisesan opening in the floor of the snorkel body.

4. The combination defined by claim 3 wherein the air control doorishinged at one edge thereof to the floor of the snorkel body for pivotalmovement upward therefrom to a canted position in which passage ofambient air through the snorkel is substantially blocked. V

5. In a thermostatically controlled heated inlet air system for the airinduction passage of an internal combustion engine: a

a carburetor having air inlet means comprising an air cleaner having asnorkel air inlet passage and including an ambient'air inlet comprisingthe open end of the snorkel and a heated air inlet comprising an openingin the floor of the snorkel body;

a notched air control door for selectively controlling the flow ofambient and heated air through the inlets, the air control door beinghinged at one edge thereof to the floor of the snorkel body for pivotalmovement upward therefrom to a canted position in which passage ofambient air through the snorkel is substantially blocked;

thermostatically controlled actuator means movably mounting the door inthe carburetor air inlet means such that the door has two fully closedpositions at the opposite extremes of its travel, one each with respectto -the ambient air inlet and the heated air inlet respectively, and aplurality of intermediate positions therebetween whereby ambientair,heated air and mixtures thereof may be admitted to the carburetor airinlet means, and

a back-up tube connected to the carburetor air inlet means for carryingvapors from the engine crankcase to the carburetor air inlet means,

the back-up tube being positioned on a side of the snorkel body with atleast a portion thereof slightly upstream of the door edge when his inthe canted position and the notch of the door is positioned at the edgethereof most proximate to 5 the back-up tubes point of attachment to thesnorkel body.

1. In a thermostatically controlled heated inlet air system for the airinduction passage of an internal combustion engine: a carburetor havingair inlet means including an ambient air inlet and a heated air inlet;an apertured air control door for selectively controlling the flow ofambient and heated air through the inlets; thermostatically controlledactuator means movably mounting the door in the carburator air inletmeans such that the door has two fully closed positions at the oppositeextremes of its travel, one each with respect to the ambient air inletand the heated air inlet respectively, and a plurality of intermediatepositions therebetween whereby ambient air, heated air and mixturesthereof may be admitted to the carburetor air inlet means, and a back-uptube connected to the carburetor air inlet means for carrying vaporsfrom the engine crankcase to the carburator air inlet means, whereby theaperture in the air coNtrol door assures the presence of at least asmall amount of ambient air flow through the air inlet means when thedoor is closed relative to the ambient air inlet and the engine isrunning thereby directing vapors from the back-up tube into thecarburetor and preventing their escape out the ambient air inlet to theatmosphere.
 2. The combination as defined by claim 1 wherein thecarburetor air inlet means comprises an air cleaner having a snorkel airinlet passage.
 3. The combination defined by claim 2 wherein the ambientair inlet comprises the open end of the snorkel and the heated air inletcomprises an opening in the floor of the snorkel body.
 4. Thecombination defined by claim 3 wherein the air control door is hinged atone edge thereof to the floor of the snorkel body for pivotal movementupward therefrom to a canted position in which passage of ambient airthrough the snorkel is substantially blocked.
 5. In a thermostaticallycontrolled heated inlet air system for the air induction passage of aninternal combustion engine: a carburetor having air inlet meanscomprising an air cleaner having a snorkel air inlet passage andincluding an ambient air inlet comprising the open end of the snorkeland a heated air inlet comprising an opening in the floor of the snorkelbody; a notched air control door for selectively controlling the flow ofambient and heated air through the inlets, the air control door beinghinged at one edge thereof to the floor of the snorkel body for pivotalmovement upward therefrom to a canted position in which passage ofambient air through the snorkel is substantially blocked;thermostatically controlled actuator means movably mounting the door inthe carburetor air inlet means such that the door has two fully closedpositions at the opposite extremes of its travel, one each with respectto the ambient air inlet and the heated air inlet respectively, and aplurality of intermediate positions therebetween whereby ambient air,heated air and mixtures thereof may be admitted to the carburetor airinlet means, and a back-up tube connected to the carburetor air inletmeans for carrying vapors from the engine crankcase to the carburetorair inlet means, the back-up tube being positioned on a side of thesnorkel body with at least a portion thereof slightly upstream of thedoor edge when it is in the canted position and the notch of the door ispositioned at the edge thereof most proximate to the back-up tube''spoint of attachment to the snorkel body.